I have a friend who drives an e21 who went through quite a few Nankangs in the duration of a month or two. He had what was in my opinion a very mild tire stretch, and I don't like massive amounts of stretch so hopefully you can get an idea of what mild is to me, and the tires did not come into contact with the fenders. I can't remember if it was three tires or four, but he had a few of them fail due to sidewall separation, and he monitors his tire pressures religiously so it was not due to improper inflation over time. I won't be buying them anytime soon.